We have studied bovine cartilage as a viscoelastic material in contact with excess saline and are currently establishing the relationship between mechanical behavior, on one hand, and location of cartilage specimen on the bovine fermoral head, on the other. We have also studied in detail the tensile stress relaxation of insoluble collagen specimens (fibers and tapes) in the presence of collagenase solutions and have determined the effect of temperature, pH, substrate crosslink density and various inhibitors of collagenase on the rate of enzymatic stress relaxation. These findings serve to support the idea that collagenolytic stress relaxation of insoluble fibrous substrate shares the characteristics of the dilute solution reaction which is well-documented in the literature.